How to make hardened parts

Abstract

The present invention relates to a method for producing cured parts from compositions comprising certain fluoroelastomers and certain bromine-containing compounds under suitable conditions to result in cured parts possessing outstanding mechanical and sealing properties and incorporating suitable amounts of bromine-containing compounds, such that when these cured parts are subjected to wear / damage, they will release Br-containing compounds that can be easily detected using suitable analytical techniques to monitor and predict their catastrophic failure. [Selection diagram] None

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 17164042.8, filed March 31, 2017, and European Patent Application No. 17170781.3, filed May 12, 2017, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to a method for producing cured parts that have the ability to interact with specific sensors in the event of wear or damage, and to the resulting cured articles that are particularly useful as smart seals. [Background technology]

[0003] Fluoroelastomers, and more particularly perfluoroelastomers, have been used for a long time in various applications that require excellent resistance to several rush conditions, such as high temperatures, chemical attack, and exposure to plasma, especially in the semiconductor manufacturing industry. In this field in particular, the possibility of monitoring the wear and damage that may be incurred in sealing parts is an essential requirement to optimize production and avoid the disposal of undesirable contaminants or non-compliant manufacturing conditions resulting in the disposal of non-standard manufactured semiconductor goods.

[0004] In fact, most seals are made of fluoroelastomers, which in their pure form are not capable of processing and / or delivering signals. Several initiatives are being taken to study materials that allow the seal to be used as a sensor or that can interact with the sensor under specific conditions, without involving the original role of the seal.

[0005] One of the main challenges is to provide a seal that can identify, for example, how worn it is. This self-monitoring is also known as "condition monitoring".

[0006] One exemplary solution is described inter alia by Freudenberg (see press release dated April 25, 2016, available at the webpage: https: / / www.fst.com / press / 2016 / freudenberg-smart-seals, downloaded on March 10, 2017); according to this document, a rod seal is provided that consists of a conductive elastomer with an effective amount of conductive filler material and an insulating outer layer, the outer layer being the sealing lip in the seal. When an electrical circuit connects the rod and the housing wall, electricity can become a measurable variable. As the rod seal moves back and forth, the sealing lip wears. When the conductive support material reaches the surface, the electrical circuit between the rod and the housing is closed - a condition that the LED can signal.

[0007] Nevertheless, this solution requires the use of peripheral devices (electrical circuitry) in direct contact with the seal to be monitored, which may be an impractical solution in some assemblies.

[0008] In this field, therefore, there is still a search for hardened parts and methods of manufacturing them that exhibit condition monitoring towards wear / structural damage while keeping manufacturing costs at a reasonable level and without compromising the original role of the seal.

[0009] German Patent No. 3823278 (Nippon Mektron Co., Ltd.) dated January 26, 1989, describes a compound comprising (a) about 30 to about 80 mole percent tetrafluoroethylene, (b) about 5 to about 60 mole percent perfluoro(lower alkyl vinyl ether), and (c) a compound having the following general formula: CF2=CFOCF2CFXOR f (Wherein, X is F or -CF3, R f -C n F 2n+1The present invention relates to a fluorine-containing elastic copolymer comprising a perfluoroether compound represented by the formula (a), and the copolymer is obtained by copolymerizing the components (a), (b) and (c) in the presence of a radical polymerization initiator. The copolymer may contain iodine or bromine from a linear iodine- or bromo-containing compound used as a chain transfer agent during copolymerization.

[0010] U.S. Patent Application Publication No. 2004014900 (3M Innovative Properties Co., Ltd.) published on January 22, 2004 (a)(i)CF2=CF-R f (In the formula, R f is fluorine or C1-C8 perfluoroalkyl), (ii) a hydrogen-containing C2-C9 olefin, wherein the CF2=CFR f and at least about 10 mole percent of an olefin, based on total moles of said olefin, (iii) an average of two or more bromine atoms per fluoropolymer chain, including one or more terminal bromine atoms, (iv) optionally, CX2=CX-R, where each X is independently H, F, or Cl, and R is a halogen or a C1-C8 alkyl or alkenyl group which may contain one or more ether linkages, (v) optionally, a fluoropolymer comprising interpolymerized units derived from a bromine-containing cure site monomer; (b) a peroxide curing agent; (c) crosslinking aid; A curable composition comprising:

[0011] U.S. Patent No. 4,906,917 (US DEPARTMENT OF ENERGY [US]) March 6, 1990 relates to a method for monitoring the degradation of an elastomer, the method comprising the steps of contacting an elastomer with a piezoelectric material having associated electrical contacts to form a vibration system, the piezoelectric material and associated contacts being part of an oscillatory circuit; vibrating the oscillatory circuit; measuring a parameter of the oscillatory circuit; and relating changes in the parameter of the oscillatory circuit to the degradation of the elastomer. Summary of the Invention [Means for solving the problem]

[0012] A first object of the present invention is therefore a method for producing a hardened shaped article [article (P)], said method comprising the steps of: (i) - at least one fluoroelastomer [fluoroelastomer (A)] comprising 0.1 to 10.0 mol % of repeating units derived from at least one cure site monomer having at least a nitrile group [monomer (CS-N)], based on the total moles of repeating units of the fluoroelastomer (A); - at least one hardening agent [agent (A)]; - at least one aromatic ring and sp 2 - at least one bromine-containing marker [marker (B)] selected from the group consisting of compounds containing at least one bromine atom bonded to a hybrid aromatic carbon. providing a fluoroelastomer composition [composition (C)] comprising: (ii) molding said composition (C) under heating at a temperature of at most 200° C. for a time of at least 30 minutes; The method includes:

[0013] The applicant has unexpectedly found that when the aforementioned curable compound, such as a fluoroelastomer containing nitrile cure sites, a cure system therefor, and a Br-containing aromatic marker are processed under the conditions as defined above, the compound can be cured to provide a cured shaped article that maintains chemically bound bromine atoms; the cured shaped article thus obtained, when subjected to wear / damage, will therefore release Br-containing contaminants that originate exclusively from seal damage, since bromine atoms are generally never contained in semiconductor raw materials or final parts, and that can be easily detected, inter alia, by online mass spectrometry, such as those routinely associated with semiconductor manufacturing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Composition (C) comprises one or more agents (A) as detailed above.

[0015] Said agent (A) is an agent capable of promoting the crosslinking of the fluoroelastomer (A) by reaction with the cure sites of the monomer (CS-N), as described above. The agent (A) may in particular be a compound carrying multiple groups reactive towards the nitrile groups of the monomer (CS-N), as described above, and / or a compound that catalytically activates the same nitrile groups of the monomer (CS-N) to react with each other.

[0016] The choice of the curing agent (A) is not particularly limited, and a person skilled in the art will select the most suitable curing agent (A) depending on the nature of the cure site of the fluoroelastomer (A).

[0017] One or more types of agent (A) can be used in the composition of the present invention. In particular, one or more types of agent (A) can be selected from those that carry multiple groups reactive towards the nitrile group of the monomer (CS-N) as described above; one or more types of agent (A) can be selected from those that catalytically activate the same nitrile group of the monomer (CS-N) to react with each other, and one or more of these two types of agent (A) can be used alone or in combination in the composition of the present invention.

[0018] When the agent (A) is selected from among the compounds possessing catalytic activity towards the activation of the nitrile group of the monomer (CS-N), as described above, the agent (A) is cat ), especially - aromatic ammonia-generating compounds, i.e. compounds capable of generating ammonia upon heating (e.g. under conditions such as those encountered during curing / post-curing); - organotin compounds (preferably tetraalkyl or tetraaryl tin compounds), such as, inter alia, allyl-, propargyl-, triphenyl-, and allenyl-tin hardeners; The compound may be selected from the group consisting of:

[0019] Reagent (A cat ) is preferably (A cat -1): Formula (U): TIFF0007599826000001.tif30161 [wherein E is O or S, preferably E is O, and R u each independently selected from the group consisting of hydrogen and C1-C6 hydrocarbon groups (particularly C1-C6 alkyl groups). (Thio)urea compounds and their salts; (A cat -2): Cycloaddition products of ammonia or primary amines with aldehydes; (A cat -3):Formula (C): TIFF0007599826000002.tif30161 (wherein E is oxygen or sulfur; R b is C1~C 36 is a hydrocarbon group, and Rc is H or a C1-C6 alkyl group. (Thio)carbamates; (A cat -4): in particular, (j) ammonium (preferably fluorine-containing) carboxylates; (jj) ammonium (preferably fluorine-containing) sulfonates; (jjj) ammonium (preferably fluorine-containing) phosphates, phosphonates or sulfonates; (jv) ammonium salts of organic and inorganic acids selected from the group consisting of ammonium salts of sulfates, carbonates, nitrates and phosphoric acids. is selected from the group consisting of:

[0020] Suitable reagents (A cat ) in: (A cat -1): As detailed above, the (thio)urea compound preferably has the formula (U-2): TIFF0007599826000003.tif29161 (wherein E' is O or S) (A cat -1-A) (thio)ureas; (A cat -2): The cycloaddition products of ammonia or primary amines with aldehydes, as detailed above, are preferably: (A cat -2-A) Formula (T): TIFF0007599826000004.tif36161 [wherein R a each is selected from the group consisting of hydrogen and C1-C6 hydrocarbon groups (particularly C1-C6 alkyl groups). Cyclic aldehyde adduct trimer of; (A cat -2-B) Formula: TIFF0007599826000005.tif25161 Hexamethylenetetramine, which is known to be the result of the addition of ammonia to formaldehyde selected from the group consisting of; (A cat -3): As detailed above, the (thio)carbamate is preferably represented by the formula (C-1): TIFF0007599826000006.tif25161(in the formula, R' d is C1~C 36 is a hydrocarbon group, preferably an optionally substituted benzyl group. (A cat -3-A) carbamates.

[0021] Agents (A) found to be particularly useful in the compositions of the present invention cat ) is as follows: (A cat -1) The preferred option from the standpoint of cost / availability / reactivity, the formula: TIFF0007599826000007.tif29161 Urea; (A cat -2) Formula: Acetaldehyde ammonia trimer in TIFF0007599826000008.tif33161; (A cat -3) Formula: TIFF0007599826000009.tif24161 Hexamethylenetetramine; (A cat -4) Formula: TIFF0007599826000010.tif32161 benzyl carbamate It is.

[0022] When the agent (A) is selected from among the compounds carrying multiple groups reactive towards the nitrile group of the monomer (CS-N), as described above, the agent (A) is func ), especially (A func -1) Formula: TIFF0007599826000011.tif29161[In the formula, - A is a bond, -SO2-, -O-, -C(O)-, or (fluoro)alkyl of 1 to 10 carbon atoms (particularly perfluoroalkyl of 1 to 10 carbon atoms, such as -C(CF3)2-); - each E, equal or different at each occurrence, is oxygen or sulfur, preferably oxygen, and the amino group and the -EH group are interchangeable in the ortho, meta or para position relative to the group A; of bis-amino(thio)phenol compounds [aminophenols (AP)]; (A func -2) Formula: TIFF0007599826000012.tif32161[In the formula, - A' is a bond, -SO2-, -O-, -C(O)-, (fluoro)alkyl of 1 to 10 carbon atoms (particularly perfluoroalkyl of 1 to 10 carbon atoms, e.g., -C(CF3)2-); - equal to or different from each other, R N Each of 12 is a hydrocarbon group, preferably an aryl group; - the amino group is interchangeable in the ortho, meta or para position relative to the group A'. of aromatic tetraamine compounds [amines (TA)]; -(A func -3) Formula: TIFF0007599826000013.tif30161 (in the formula, R a1 is -OH or -H, R a2 is H or NH2, and E is a C1-C 18 (a divalent group) of bis-amidoxime / amidine / amidrazone compounds; -(A func -4) Formula: TIFF0007599826000014.tif22161(in the formula, E b C1-C optionally containing a fluorine atom 18 is a divalent group, R b is optionally fluorinated, C1-C 12 (Based on Bis-imidoyl amidine compounds The compound may be selected from the group consisting of:

[0023] Bis-amidoxime / amidine / amidrazone compounds (A func -3), in particular, (A func -3-A):Formula: TIFF0007599826000015.tif30161 [wherein Rf is a divalent fluorinated alkylidene group, preferably n is 1 to 10, formula -(CF2) n - or in which R f is a (per)fluorooxyalkylene group, preferably, -(CFX), where X is F or -CF3; n and m are zero or an integer, provided that n+m is 1 to 100; and m is 1 or 2. p (OCF2CFX) n (OCFX) m O-(CFX) p - is a group selected from Fluorinated bis-amidoxime compounds; (A func -3-B) Formula: TIFF0007599826000016.tif34161[in formula, J a is a bond, -SO2-, -O-, -C(O)-, or (fluoro)alkyl of 1 to 10 carbon atoms (specifically, perfluoroalkyl of 1 to 10 carbon atoms, e.g., -C(CF3)2-). of aromatic bis-amidoxime compounds; (A func -3-C):Formula: TIFF0007599826000017.tif29161[where, R f is a divalent fluorinated alkylidene group, preferably of the formula -(CF2) where n is 1 to 10. n - or in which R f is a (per)fluorooxyalkylene group, preferably -CFx, where X is F or -CF3; n and m are zero or integers, with the proviso that n+m is 1 to 100; and m is 1 or 2. p (OCF2CFX) n (OCFX) m O-(CFX) p - is a group selected from Fluorinated bis-amidrazone compounds; (A func -3-D) formula: TIFF0007599826000018.tif37161[in formula, J c is a bond, -SO2-, -O-, -C(O)-, or (fluoro)alkyl of 1 to 10 carbon atoms (specifically perfluoroalkyl of 1 to 10 carbon atoms, e.g., -C(CF3)2-). Aromatic bis-amidrazone compounds can be mentioned.

[0024] According to certain preferred embodiments, the agent (A) is an aminophenol (AP), as detailed above.

[0025] The aminophenol (AP) may be selected from the group consisting of 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]bis(2-aminophenol); 4,4'-sulfonylbis(2-aminophenol); 3,3'-diaminobenzidine, 3,3',4,4'-tetraaminobenzophenone.

[0026] Particularly preferred aminophenols (AP) have the formula: The compound has the alias bis-aminophenol AF, 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]bis(2-aminophenol), having the TIFF0007599826000019.tif29161.

[0027] The composition (C) contains one or more markers (B) as detailed above, i.e. at least one aromatic ring and at least one sp 2 - at least one bromine atom bonded to a hybridized aromatic carbon.

[0028] Without being bound by this theory, the Applicant has surprisingly found that marker (B), as detailed above, does not adversely affect the curing efficiency under the specific conditions enumerated above (at least 30 minutes at a temperature of at most 200°C) found to be effective for achieving substantial curing, nor does it undergo any significant evaporative loss or decomposition, thus ensuring in the final rubber part thus obtained the presence of bromine-containing compounds, which, if and when released in certain environments for any reason, for example due to wear and / or material degradation, can be easily detected by different analytical techniques, such as mass spectrometry in particular.

[0029] This is particularly advantageous in semiconductor manufacturing where, on the one hand, fluoroelastomers are widely used as sealing materials, whereas the conditions are extremely harsh and demanding, e.g., plasma radiation, HF and other etching gas exposure, and furthermore extreme cleanliness and the absence of any type of contaminant, including waste from sealing damaged equipment, are essential to meet quality standards.

[0030] As stated, marker (B) contains at least one bromine atom. Marker (B) may contain one or more bromine atoms.

[0031] In fact, the Applicant has determined that said at least one bromine atom of the marker (B) is an aromatic sp 2 It has been found that when linked to an aromatic moiety by said bond to a hybridized carbon, the heat resistance of said Br-C bond is enhanced, so that release of bromine from composition (C) and / or from the cured parts derived therefrom occurs primarily and substantially due to catastrophic failure of the cured parts derived therefrom and not during the curing process, provided that the processing conditions defined above are observed.

[0032] As stated, marker (B) contains at least one aromatic ring. Marker (B) may contain one or more aromatic rings; when marker (B) contains more than one aromatic ring, said aromatic rings may be fused or linked by bonds or by any type of bridging group.

[0033] The marker (B) may contain a fluorine atom.

[0034] The marker (B) generally has the following formula (B-1): TIFF0007599826000020.tif31161 (in the formula, Ar B1 is an aromatic group, optionally containing a fluorine atom; and n is zero or an integer from 1 to 4. Follow.

[0035] Among the preferred markers (B) there is especially the formula: TIFF0007599826000021.tif31161 4,4'-dibromooctafluorobiphenyl and the formula: Reference may be made to 4-bromobiphenyl in TIFF0007599826000022.tif19161.

[0036] Composition (C) generally comprises: - a marker (B), as detailed above, generally in an amount ranging from 0.10 to 10 phr, preferably from 0.25 to 6 phr, relative to the fluoroelastomer (A); - the agent (A), as detailed above, in an amount ranging from 0.10 to 10 phr, preferably from 0.25 to 5 phr, relative to the fluoroelastomer (A); Includes.

[0037] Composition (C) comprises one or more compounds (A) as detailed above.

[0038] For the purposes of the present invention, the term "(per)fluoroelastomer" [fluoroelastomer (A)] is intended to refer to a fluoropolymer resin serving as a basic building block for obtaining true elastomers, said fluoropolymer resin comprising more than 10% by weight, preferably more than 30% by weight, of repeat units deriving from at least one ethylenically unsaturated monomer containing at least one fluorine atom (hereinafter (per)fluorinated monomer) and, optionally, from at least one ethylenically unsaturated monomer not containing a fluorine atom (hereinafter hydrogen-containing monomer).

[0039] True elastomers are defined by the ASTM, Special Technical Bulletin, No. 184 standard as materials which can be stretched, at room temperature, to twice their inherent length and which simultaneously return to within 10% of their original length as soon as they are released after holding them under tension for five minutes.

[0040] Generally, the fluoroelastomer (A) comprises, in addition to repeat units derived from the monomers (CS-N), as detailed above, repeat units derived from at least one (per)fluorinated monomer, said (per)fluorinated monomer being generally - C2 to C8 fluoro- and / or perfluoroolefins, such as tetrafluoroethylene (TFE), hexafluoropropene (HFP), pentafluoropropylene, and hexafluoroisobutylene; - C2-C8 hydrogen-containing monofluoroolefins such as vinyl fluoride, 1,2-difluoroethylene, vinylidene fluoride (VDF) and trifluoroethylene (TrFE); - Formula CH2=CH-R f0 (In the formula, R f0 is a C1-C6 (per)fluoroalkyl or a C1-C6 (per)fluorooxyalkyl having one or more ether groups; - chloro- and / or bromo- and / or iodo-C2-C6 fluoroolefins, such as chlorotrifluoroethylene (CTFE); - Formula CF2=CFOR f1 (In the formula, R f1 is C1-C6 fluoro- or perfluoroalkyl, for example, -CF3, -C2F5, -C3F7); - Formula CH2=CFOR f1 (In the formula, R f1 is C1-C6 fluoro- or perfluoroalkyl, for example, -CF3, -C2F5, -C3F7), hydrofluoroalkyl vinyl ethers according to - Formula CF2=CFOX0 (wherein X0 is a C1-C alkyl group having one or more ether groups) 12 Oxyalkyl or C1-C 12 (per)fluorooxyalkyl) vinyl ethers according to the formula CF2=CFOCF2OR f2 (In the formula, R f2is C1-C6 fluoro- or perfluoroalkyl, for example C1-C6 (per)fluorooxyalkyl having one or more ether groups, such as -CF3, -C2F5, -C3F7 or -C2F5-O-CF3; - Formula CF2 = CFOY0 (wherein Y0 is C1 to C 12 Alkyl or (per)fluoroalkyl, or C1-C 12 Oxyalkyl or C1-C 12 (per)fluorooxyalkyl, said Y0 group containing a carboxylic acid group or a sulfonic acid group in its acid, acid halide or salt form); - Formula: TIFF0007599826000023.tif33161 (wherein R f3 , R f4 , R f5 , R f6 each independently being a C1-C6 fluoro- or per(halo)fluoroalkyl, optionally containing a fluorine atom, one or more oxygen atoms, e.g., -CF3, -C2F5, -C3F7, -OCF3, -OCF2CF2OCF3) (per)fluorodioxole is selected from the group consisting of:

[0041] Examples of hydrogen-containing monomers are hydrogen-containing alpha-olefins, diene monomers, styrene monomers, such as ethylene, propylene, 1-butene, among others, with alpha-olefins being typically used.

[0042] The fluoroelastomers (A) are generally amorphous products, i.e., with low crystallinity (less than 20% by volume of crystalline phase) and glass transition temperatures (T g In most cases, the fluoroelastomer (A) has a T of advantageously less than 10° C., preferably less than 5° C., more preferably 0° C. g has.

[0043] The fluoroelastomer (A) is preferably (1) VDF-based copolymers, in which VDF is a copolymer of the monomers (CS-N), as detailed above, and (a) C2-C8 perfluoroolefins such as tetrafluoroethylene (TFE) and hexafluoropropylene (HFP); (b) Hydrogen-containing C2-C8 olefins, such as vinyl fluoride (VF), trifluoroethylene (TrFE), and hexafluoroisobutene (HFIB), with the formula CH2=CH-R f (In the formula, R f is a C1-C6 perfluoroalkyl group; (c) C2-C8 fluoroolefins containing at least one of iodine, chlorine, and bromine, such as chlorotrifluoroethylene (CTFE); (d) Formula CF2=CFOR f (In the formula, R f is a C1-C6 (per)fluoroalkyl group, preferably CF3, C2F5, or C3F7 (per)fluoroalkyl vinyl ether (PAVE); (e) Formula CF2=CFOX (wherein X is a C1-C 12 (per)fluoro-oxy-alkyl vinyl ethers (perfluoro)-oxyalkyl, for example, perfluoro-2-propoxypropyl); (f) Formula: TIFF0007599826000024.tif36161 (wherein R f3 , R f4 , R f5 , R f6 are each independently selected from the group consisting of fluorine atoms and C1-C6 (per)fluoroalkyl groups, optionally containing one or more oxygen atoms, such as -CF3, -C2F5, -C3F7, -OCF3, -OCF2CF2OCF3, among others. (Per)fluorodioxoles having the formula: (g) Formula: CF2=CFOCF2OR f2 (In the formula, Rf2 is selected from the group consisting of C1-C6 (per)fluoroalkyl; C5-C6 cyclic (per)fluoroalkyl; and C2-C6 (per)fluorooxyalkyl containing at least one catenary oxygen atom; R f2 is preferably -CF2CF3(MOVE1); -CF2CF2OCF3(MOVE2); or CF3(MOVE3) (per)fluoro-methoxy-vinyl ether (hereinafter MOVE); (h) C2-C8 non-fluorinated olefins (Ol), such as ethylene and propylene and (2) TFE-based copolymers, in which TFE is copolymerized with monomer (CS-N), as detailed above, and at least one additional comonomer selected from the group consisting of (c), (d), (e), (g), (h) and (i), as detailed above. is selected among.

[0044] The fluoroelastomer (A) is generally chosen among the TFE-based copolymers, as detailed above.

[0045] Optionally, the fluoroelastomer (A) of the present invention may also have the general formula: TIFF0007599826000025.tif22161, where R1, R2, R3, R4, R5 and R6, which are equal to or different from each other, are H or C1-C5 alkyl; Z is a linear or branched C1-C alkyl group, preferably at least partially fluorinated, optionally containing an oxygen atom. 18 (hydro)carbon group (including alkylene or cycloalkylene group), or (per)fluoro(poly)oxyalkylene group containing one or more catenary ether bonds) The repeat unit may be derived from a bis-olefin [bis-olefin (OF)] having the formula:

[0046] The bis-olefins (OF) are preferably represented by the formula (OF-1), the formula (OF-2) and the formula (OF-3): TIFF0007599826000026.tif34161 [wherein j is an integer of 2 to 10, preferably 4 to 8, and is equal to or different from each other; R1, R2, R3, and R4 are each H, F, or C. 1~5 alkyl or (per)fluoroalkyl groups; TIFF0007599826000027.tif34161 [wherein each A, which is equal to or different from each other and at each occurrence, is independently selected from F, Cl, and H; each B, which is equal to or different from each other and at each occurrence, is independently selected from F, Cl, H, and OR B (where R B is a branched or linear alkyl group which may be partially, substantially or completely fluorinated or chlorinated; E is an optionally fluorinated divalent group having 2 to 10 carbon atoms, in which ether bonds may be inserted; preferably, E is -(CF2) m - group; a preferred bis-olefin of type (OF-2) is F2C=CF-O-(CF2)5-O-CF=CF2], TIFF0007599826000028.tif34161 [wherein E, A and B have the same meaning as defined above; R5, R6, R7 are H, F or C; 1~5 alkyl or (per)fluoroalkyl group. The compound is selected from the group consisting of those conforming to the formula:

[0047] Among the cure site monomers of type (CS-N), as detailed above, contained in the fluoroelastomer (A), preferred monomers are (per)fluorinated, especially (CS-N1)X CN is F or CF, m is 0, 1, 2, 3 or 4; and n is an integer from 1 to 12, CN ) m -O-(CF2) nPerfluorovinyl ethers containing a nitrile group of -CN; (CS-N2)X CN is F or CF3, and m' is 0, 1, 2, 3 or 4, CN ) m’ Perfluorovinyl ether containing a nitrile group, -O-CF2-CF(CF3)-CN Specific examples of cure site monomers of type CS-N1 and CS-N2 suitable for the purposes of the present invention are, inter alia, those described in U.S. Pat. No. 4,281,092 (DU PONT) of July 28, 1981, U.S. Pat. No. 4,281,092 (DU PONT) of July 28, 1981, U.S. Pat. No. 5,447,993 (DU PONT) of September 5, 1995 and U.S. Pat. No. 5,789,489 (DU PONT) of August 4, 1998.

[0048] A preferred cure site monomer (CS-N) has the formula: CF2=CF-O-CF2-CF(CF3)-O-CF2-CF2-CN The compound is perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene) (8-CNVE).

[0049] Exemplary preferred fluoroelastomers (A) that can be used in the compositions of the present invention have the following monomer composition (in mole %, based on the total moles of repeating units): (i) Tetrafluoroethylene (TFE): 50-80%; (per)fluoroalkyl vinyl ether (PAVE): 15-50%; Monomer (CS-N): 0.1-10%; Bis-olefin (OF): 0-5%; (ii) Tetrafluoroethylene (TFE): 20-70%; (per)fluoro-methoxy-vinyl ether (MOVE): 25-75%; (per)fluoroalkyl vinyl ether (PAVE): 0-50%; Monomer (CS-N): 0.1-10%; Bis-olefin (OF): 0-5% It has the following characteristics.

[0050] Composition (C) may further comprise additional components that may be commonly used for the curing of fluoroelastomers; more specifically, composition (C) generally comprises: (a) one or more metal basic compounds, generally in an amount of 0.5 to 15 phr, preferably 1 to 10 phr, relative to 100 parts by weight of the fluoroelastomer (A); the metal basic compounds are generally selected from the group consisting of (j) oxides or hydroxides of divalent metals, such as the oxides or hydroxides of Mg, Zn, Ca or Pb, and (jj) metal salts of weak acids, such as the stearates, benzoates, carbonates, oxalates or phosphites of Ba, Na, K, Pb, Ca; (b) one or more acid acceptors which are not metal basic compounds, generally in an amount of from 0.5 to 15 phr, preferably from 1 to 10 phr, relative to 100 parts by weight of the fluoroelastomer (A); these acid acceptors are generally chosen from nitrogen-containing organic compounds, such as 1,8-bis(dimethylamino)naphthalene, octadecylamine, among others, as described in EP 708797 A (DU PONT) of May 1, 1996; (c) Other conventional additives, such as fillers, thickeners, pigments, antioxidants, stabilizers, processing aids, etc. It may further include.

[0051] As said, the present invention relates to a process for the manufacture of a cured shaped article [article (P)], said process in particular comprising a step (ii) of shaping a composition (C) as detailed above under heating at a temperature of at most 200° C. for a time of at least 30 minutes.

[0052] The expression "molding", when used in relation to composition (C), is intended herein to encompass all methods of producing / shaping an article starting from said composition (C), including any post-treatment or further processing, which will ultimately result in a hardened shaped article, as detailed above.

[0053] The molding process may include injection molding, compression molding, extrusion, coating, screen printing, forming-in-place, calendering of composition (C) into the desired shaped article, which advantageously undergoes vulcanization (curing) during the process itself and / or in a subsequent step (post-treatment or post-cure) to advantageously convert the relatively soft, weak, fluoroelastomer uncured composition into a finished article made of a non-tacky, strong, insoluble, chemically and heat resistant cured fluoroelastomer material.

[0054] Nevertheless, it remains a requirement of the process of the present invention that said shaping is carried out under heating at a temperature of at most 200°C, preferably at most 195°C, more preferably at most 190°C, even more preferably at most 185°C and / or at a temperature of at least 160°C, preferably at least 165°C, more preferably at least 170°C.

[0055] In the forming step of the method of the present invention, said heating is continued for a duration of at least 30 minutes, preferably at least 45 minutes, more preferably at least 1 hour.

[0056] There is no specific upper limit that must be imposed on the duration of the heating step; the skilled person will ensure that the duration chosen is consistent with the general industry requirements to result in an adequate manufacturing throughput of shaped articles (P) of constant and adequate quality. Thus, in the forming step of the method of the invention, said heating generally continues for a duration of less than 16 hours, preferably less than 14 hours, preferably less than 12 hours.

[0057] Furthermore, the present invention relates to cured shaped articles obtained from the composition (C) using the method as detailed above. These cured articles may be sealing articles such as O-rings, packings, gaskets, diaphragms, shaft seals, valve stem seals, piston rings, crankshaft seals, camshaft seals and oil seals, or flexible hoses or other items such as piping and tubes, especially conduits for the delivery of hydrocarbon fluids and fuels.

[0058] Additionally, the present invention relates to a method for detecting wear / damage in a cured shaped article (P) as detailed above, said method comprising the step of monitoring the release of bromine-containing compounds therefrom.

[0059] The technique for monitoring the release of bromine-containing compounds is not particularly limited and can be based on standard analytical techniques. Mass spectrometry is particularly suitable for detecting bromine-containing compounds due to the characteristic double peak associated with ions that have lost a bromine atom.

[0060] To the extent that the disclosure of any of the patents, patent applications, and publications incorporated herein by reference contradicts this description to the extent that it may render a term unclear, this description shall control.

[0061] The invention will now be described in more detail with reference to the following examples, the purpose of which is merely illustrative and not limiting the scope of the invention.

[0062] raw materials Bis-aminophenol AF (hereinafter BOAP) was supplied by Apollo Scientific and was used as received.

[0063] 4,4'-Dibromo-octafluorobiphenyl (hereinafter DBOFBP) was supplied by Apollo Scientific and used as received.

[0064] 4-Bromobiphenyl (hereafter BBP) was supplied by Sigma Aldrich and was used as received.

[0065] Preparative Example 1 - Preparation of elastomers containing nitrile groups A 5 liter reactor equipped with a mechanical stirrer operating at 630 rpm was charged with 3.1 liters of demineralized water and a solution of 1,2-dichlorophenyl ether of the formula: CF2ClO(CF2-CF(CF3)O)n(CF2O). m 7.4 ml of perfluoropolyoxyalkylene having acid end groups of formula CF2COOH (wherein n / m=10 and has an average molecular weight of 600), 1.9 ml of 30% v / v aqueous NH4OH solution, 17.4 ml of demineralized water, and a mixture of 1,2-difluorophenyl ether (CF3O(CF2CF(CF3)O)n(CF2O) with n / m=20 and an average molecular weight of 450, was added. m 31 ml of microemulsion, previously obtained by mixing CF3 with 4.3 ml of GALDEN® D02 perfluoropolyether, were introduced. The reactor was heated and maintained at a set point temperature of 80° C.; a mixture of tetrafluoroethylene (TFE) (35 mol%), perfluoromethylvinylether (MVE) (64.3 mol%) and ethane (0.7 mol%, chain transfer agent) was then added to reach a final pressure of 21 bar (2.1 MPa). 0.31 g of ammonium persulfate (APS) as initiator was then introduced. The pressure was maintained at a set value of 21 bar by continuously feeding a gas mixture of TFE (57.5 mol%) and MVE (42.5 mol%) up to a total of 1350 g, and 129 g of 8-CNVE was fed to the reactor starting from the start of the polymerization in 20 portions for each 5% increase in conversion. Further, 0.16 g of APS was introduced at 15%, 40% and 55% conversion of the gas mixture. The reactor was then cooled, vented and the latex was recovered. The latex was coagulated with nitric acid as coagulant, the polymer was separated from the aqueous phase, washed with demineralized water and dried in a convection oven at 120° C. for 24 hours. The composition of the obtained polymer was found by NMR analysis to be 60.8 mol % TFE, 38.0 mol % MVE, 1.2 mol % 8-CNVE, and the Mooney viscosity at 121° C. is 50 MU.

[0066] General Mixing and Curing Procedure The fluoroelastomer of Preparative Example 1 was compounded with the ingredients as detailed below in a two-roll open mill. The plaques were cured in a pressure mold at the conditions detailed in the table below and, for comparative purposes, were post-treated in an air circulating oven as detailed below. M L = minimum torque (lb × in) M H = Maximum torque (lb×in) t S2 = Scorch Time, M L Time for 2 unit rise from (seconds); t 02 = time to 2% cure (sec); t 50 = time to 50% cure (sec); t 90 = time to 90% cure (sec); t 95 = Time to 95% cure (sec) The tensile properties were measured on specimens punched from the plaques according to the ASTM D 412C standard. TS is the tensile strength in MPa; M 50 is the elastic modulus in MPa at 50% elongation; M 100 is the elastic modulus in MPa at 100% elongation; EB is the elongation at break in %. Compression set (CS) values ​​were measured on O-rings (#214 class) according to ASTM D 395-B method at a temperature of 200° C.; the values ​​in the table are the average values ​​of measurements made on four specimens.

[0067] TIFF0007599826000029.tif97170

[0068] TIFF0007599826000030.tif113170

[0069] Bromine content measurement For comparison, the Br content was measured by XRF at the conditions detailed above: (i) after compounding the elastomer with the ingredients listed in Table 1, (ii) after curing / molding; and (iii) after post-curing at 290° C. The results are summarized in the table below.

[0070] TIFF0007599826000031.tif72170

[0071] The data contained in the table below demonstrates that the method of producing cured shaped articles according to the present invention is effective in substantially retaining bromine compounds in the cured parts.

[0072] Measurement of mechanical and sealing properties The data below, recalling the mechanical and sealing properties for the cured parts obtained as detailed above, well demonstrates that the method of the present invention results in cured shaped parts that retain all the outstanding properties of the cured fluoroelastomer material.

[0073] TIFF0007599826000032.tif76170

Claims

1. A method for producing a cured shaped article [article (P)], said method comprising the steps of: (i) at least one fluoroelastomer [fluoroelastomer (A)] comprising from 0.1 to 10.0 mol % of repeating units derived from at least one cure site monomer having at least a nitrile group [monomer (CS-N)], based on the total moles of repeating units of the fluoroelastomer (A); at least one hardening agent [agent (A)]; - Below formula (B-1): (In the formula, Ar B1 is an aromatic group which may contain a fluorine atom; and n is zero or an integer of 1 to 4.) At least one bromine-containing marker [marker (B)] according to providing at least one fluoroelastomer composition [composition (C)] comprising: (ii) molding said composition (C) under heating at a temperature of at most 200° C. for a time of at least 30 minutes; The method includes:

2. The agent (A) is selected from among compounds possessing catalytic activity toward the activation of the nitrile group of the monomer (CS-N), and the agent (A) is ｃａｔ ) is called, ammonia-generating organic compounds, i.e. compounds capable of generating ammonia on heating; - organotin compounds (preferably tetraalkyl or tetraaryl tin compounds), such as, inter alia, allyl-, propargyl-, triphenyl-, and allenyl-tin hardeners. The method of claim 1 , wherein the compound is selected from the group consisting of:

3. The reagent (A ｃａｔ )but, (A ｃａｔ -1): Formula (U): wherein E is O or S, preferably E is O, and R ｕ Each of １ ~C ６ independently selected from the group consisting of hydrocarbon groups. (Thio)urea compounds of the formula (I) and their salts; (A ｃａｔ -2): Cycloaddition products of ammonia or primary amines with aldehydes; (A ｃａｔ -3): Formula (C): where E is oxygen or sulfur; R ｂ is C １ ~C ３６ is a hydrocarbon group, and Rc is H or C １ ~C ６ is an alkyl group) (Thio)carbamates of; (A ｃａｔ -4): especially (j) ammonium carboxylates; (jj) ammonium sulfonates; (jjj) ammonium phosphates, phosphonates or sulfonates; (jv) ammonium salts of organic and inorganic acids selected from the group consisting of ammonium salts of sulfates, carbonates, nitrates and phosphoric acids. The method of claim 2, wherein the compound is selected from the group consisting of:

4. Reagent (A ｃａｔ ) is selected from the group consisting of: (A ｃａｔ -1): As detailed above, the (thio)urea compound is preferably represented by the formula (U-2): (wherein E′ is O or S). (A ｃａｔ -1-A) (thio)ureas; (A ｃａｔ -2): Cycloaddition products of ammonia or primary amines with aldehydes, preferably (A ｃａｔ -2-A) formula (T): [wherein R ａ Each of １ ~C ６ Hydrocarbon groups (especially C １ ~C ６ alkyl group)] Cyclic aldehyde adduct trimer of (A ｃａｔ -2-B) Formula: Hexamethylenetetramine selected from the group consisting of: (A ｃａｔ -3): As detailed above, the (thio)carbamate is preferably of the formula (C-1): (In the formula, R' ｄ is C １ ~C ３６ is a hydrocarbon group, preferably an optionally substituted benzyl group. (A ｃａｔ -3-A) selected from the group consisting of carbamates; The method according to claim 3.

5. The agent (A) is selected from compounds carrying a plurality of groups reactive towards the activation of the nitrile group of the monomer (CS-N), and the agent (A) is ｆｕｎｃ ) is called, (A ｆｕｎｃ -1) Formula: [In the formula: - A is a bond, -SO ２ -, -O-, -C(O)-, or (fluoro)alkyl of 1 to 10 carbon atoms, preferably perfluoroalkyl of 1 to 10 carbon atoms, more preferably -C(CF ３ ) ２ - and each E, equal or different at each occurrence, is oxygen or sulfur, preferably oxygen, and wherein the amino group and the -EH group are interchangeable in the ortho, meta or para position relative to the group A; bis-amino(thio)phenol compounds [aminophenols (AP)]; (A ｆｕｎｃ -2) Formula: A' is a bond, -SO ２ -, -O-, -C(O)-, (fluoro)alkyl of 1 to 10 carbon atoms, preferably perfluoroalkyl of 1 to 10 carbon atoms, more preferably -C(CF ３ ) ２ - and - R, which are equal to or different from each other Ｎ Each of １ ~C １２ a hydrocarbon group, preferably an aryl group; The amino groups are interchangeable in the ortho, meta or para positions relative to the group A'. Aromatic tetraamine compounds [amines (TA)] of the formula: - (A ｆｕｎｃ -3) Formula: (In the formula, R ａ１ is —OH or —H, R ａ２ is H or NH ２ and E optionally contains a fluorine atom; １ ~C １８ (a divalent group) Bis-amidoxime / amidine / amidrazone compounds of the formula: - (A ｆｕｎｃ -4) Formula: (In the formula, E ｂ C optionally contains fluorine atoms; １ ~C １８ is a divalent group, R ｂ is optionally fluorinated, １ ~C １２ (Based on Bis-imidoyl amidine compounds of The method of claim 1 , wherein the compound is selected from the group consisting of:

6. The reagent (A ｆｕｎｃ ) has the formula: The method according to claim 5, wherein the compound is 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]bis(2-aminophenol) having the formula:

7. The marker (B) has the formula: and 4,4'-dibromooctafluorobiphenyl of the formula: The method according to any one of claims 1 to 6, wherein the 4-bromobiphenyl is selected from the group consisting of

8. The composition (C) is a marker (B), generally in an amount ranging from 0.10 to 10 phr, preferably from 0.25 to 6 phr, relative to the fluoroelastomer (A); and / or agent (A) in an amount ranging from 0.10 to 10 phr, preferably from 0.25 to 5 phr, relative to the fluoroelastomer (A); The method according to any one of claims 1 to 7, comprising:

9. The cure site monomer of type (CS-N) is (CS-N1)X ＣＮ is F or CF ３ wherein m is 0, 1, 2, 3 or 4; and n is an integer from 1 to 12; ２ =CF-(OCF ２ CFX ＣＮ ) ｍ -O-(CF ２ ) ｎ Perfluorovinyl ethers containing a nitrile group of -CN; (CS-N2)X ＣＮ is F or CF ３ and m′ is 0, 1, 2, 3 or 4; ２ =CF-(OCF ２ CFX ＣＮ ) ｍ’ -O-CF ２ -CF (CF ３ Perfluorovinyl ether containing a nitrile group of -CN The method according to any one of claims 1 to 8, wherein the compound is selected from the group consisting of:

10. 10. The method according to any one of claims 1 to 9, wherein said step of molding comprises at least one of the steps of injection molding, compression molding, extrusion, coating, screen printing, pouring, calendering said composition (C) into a desired shaped article.

11. The method according to any one of the preceding claims, wherein the shaping is carried out under heating at a temperature of at most 195°C, more preferably at most 190°C, even more preferably at most 185°C and / or at a temperature of at least 160°C, preferably at least 165°C, more preferably at least 170°C.

12. 12. The method according to any one of claims 1 to 11, wherein the heating is continued for a duration of at least 45 minutes, more preferably at least 1 hour, and / or for a duration of less than 16 hours, preferably less than 14 hours, preferably less than 12 hours.

13. A method according to any one of claims 1 to 12, wherein the hardened shaped article is selected from the group consisting of sealing articles such as O-rings, packings, gaskets, diaphragms, shaft seals, valve stem seals, piston rings, crankshaft seals, camshaft seals and oil seals, or is flexible hoses or other items such as piping and tube materials, in particular conduits for the delivery of hydrocarbon fluids and fuels.

14. A method for detecting wear / damage in a hardened shaped article (P) obtained from said composition (C) using a method according to any one of claims 1 to 13, said method comprising the step of monitoring the release of bromine-containing compounds therefrom.

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